body{
    margin: 0;
    width: 100%;
    height: 100%;
}
div{
    float: left;
}
#main{
    width: 100%;
    height: 100%;
}
#top{
    width: 100%;
    height: 100px;
    background-color: rgba(0,0,0,0.5);
    horiz-align: center;
}
#search_box{
    width: 80%;
    height: 50%;
    border: 5px solid white;
}